Improve link in How to Build Your First Image on Apertis

Signed-off-by: Martyn Welch <martyn.welch@collabora.com>

content/guides/how_to_build_your_first_image.md

@@ -7,8 +7,14 @@ title = "How to Build Your First Image on Apertis"
 +++
 
 This guide aims to explain how to build your first image on Apertis
-using the GitLab UI. A comprehensive documentation to manually build
-a customized image is available at [Image building]( {{< ref "image_building.md" >}} ).
+using the GitLab UI.
+
+{{% notice note %}}
+This guide details how to customise an image designed to run on the existing
+reference hardware. If you are looking for documentation on  how to manually
+build a customized image for other hardware, see the
+[Image building]( {{< ref "image_building.md" >}} ) guide.
+{{% /notice %}}
 
 This document will explain how to create a GitLab account and
 how to use its UI and pipelines to modify and create a custom Apertis